Recent Japan Meteorological Agency forecasts point to a 33–35°C range for Tokyo on July 21 amid a persistent heatwave fueled by a strong Pacific high-pressure system advecting warm, humid air northward. This setup, combined with above-normal seasonal baselines from a warming climate and northward-shifted westerlies, underpins trader clustering around 34–36°C outcomes. Key differentiators include variable cloud cover or scattered showers that could cap daytime maxima, urban heat-island amplification in central districts, and minor model spread in boundary-layer moisture. Updated model runs and official briefings over the next 48 hours will refine these probabilities as resolution approaches.